Can one get electric shock by touching only one terminal of AC generator ?
Welcome to PF;
To get an electric shock there needs to be some path for the electricity to get from a high voltage place to a low voltage place - through you. The other terminal is a low voltage place but the ground will do just as well.
But how the circuit gets complete in this case.
"The circuit" meaning the route between the terminals of the generator?
That does not get completed. You don't have to have charges ending up where they started in order to get an electric current.
Electricity flows from high voltage to low voltage.
But if electrons coming out from one terminal don't enter the other terminal, it would lead to accumulation of +ve charge on the terminal. How can that happen?
There are a number of things highlighted in this question.
If it were a DC power supply, with nothing connected between the terminals, then charge does accumulate at the terminals.
Electrons are supplied at the negative terminal, and removed from the negative (-ve) terminal - for DC. Not the +ve terminal. Notice how I've been careful to say "charges"?
If you connect either DC terminal to, say, the ground, charges will flow from that terminal to the ground. You do not have to connect the other one. If the connection is you, you feel an electric shock.
But you are not talking about DC. Your question was about AC.
In AC there is no such thing as +ve or -ve terminals.
With nothing connected across the terminals of an AC supply, charges get added and then removed from each terminal as (most commonly) a sine-wave.
When you connect either terminal to a large supply of charge - like the ground, the AC power supply will happily shunt charges to and from that. There is no need to connect the other terminal. If that connection is you, you feel an electric shock.
I'm getting worried about you: you already know it is not safe to grab a live wire right?
Well like Simon said , DC builds up charge and static electricity does too , like your clothes on days when it's a considerable amount of moisture in air.
AC does not, as any other time/amplitude varying current.
Whether you will get shocked or not when touching a live wire depends on many factors , like the voltage level in that wire, the insulation of your body(individual , may vary from human to human) the insulation of your clothes , skin and the pavement your standing on.
In many factories workers who work on machines that are powered from 3 phase ac stand on rubber carpets, In terms of electricity their standing in "air" If you touch just one wire at a time like one of the phases and if you are standing on a sufficient insulation , according to theory nothing should happen.I once touched the live wire of ac while working on a project at my house but I have a wooden floor, so i felt no shock , the floor was sufficient to insulate me so not let the current flow, there was no path for the current created.I have 230v in the live wire of wall socket.
Although I don't want to encourage any one to do this AND REMEMBER IT IS DANGEROUS, as the electrical resistance of the human body is different some have it higher some have it lower and the conditions of which someone receives the shock are also different.
@Simon I don't think that any terminal of the ac will shock you or push charges through , only the phase terminal, the neutral wire doesn't give u shock if it's wired correctly there should be no voltage on it, sometimes under heavy and unbalances loads maybe a tiny bit of voltage/current.
When you put the screwdriver-tester in the phase wire it glows because current has a path to go through the little bulb , through your body to ground, when putting it in neutral it usually doesn't glow hence no current is flowing.
That's mains power, which can be special that way ... in AC generators, the subject, the electrons can be (and usually are) supplied to both terminals.
... it can get quite complicated.
(less formally: http://answers.yahoo.com/question/index?qid=20090827051528AAq1ijI )
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